/Engine/Source/Runtime/MovieScene/Public/EntitySystem/MovieSceneEntityManager.h
Free all entities defined by the specified operation
The number of entities released
int32 FreeEntities ( const [FFreeEntityOperation](API\Runtime\MovieScene\EntitySystem\FFreeEntityOperation) & Operation, [TSet](API\Runtime\Core\Containers\TSet)< [FMovieSceneEntityID](API\Runtime\MovieScene\EntitySystem\FMovieSceneEntityID) > * OutFreedEntities )